Synthesis of Nanoporous Li4Ti5O12–TiO2 Composites for High‐Performance Lithium‐Ion‐Battery Anodes

This work reports the synthesis of Li4Ti5O12–TiO2 nanoporous composites through an effective, inexpensive, and easily scalable approach. The as-synthesized products were calcined under a nitrogen atmosphere at 700, 750, or 800 °C. When used as anode materials for lithium-ion batteries, the 750 °C nitrogen-treated Li4Ti5O12–TiO2 sample showed significantly improved capacity as well as good rate capability and cycling stability compared with other samples. It delivered capacities of 220 and 213 mAh g−1 at a current density of 30 mA g−1 when tested at room temperature and 55 °C, respectively. It still had capacities of 184 and 197 mAh g−1 after 50 cycles, which was noticeably higher than the known theoretical capacity of pure Li4Ti5O12 (175 mAh g−1). The excellent electrochemical performance of the nitrogen-treated nanoporous composites could be attributed to the improved morphology, dual phase crystal structure, and the presence of surface defects from nitrogen treatment.